Release 4.14 arch/x86/kernel/cpu/scattered.c

/*
 *      Routines to identify additional cpu features that are scattered in
 *      cpuid space.
 */
#include <linux/cpu.h>

#include <asm/pat.h>
#include <asm/processor.h>

#include <asm/apic.h>


struct cpuid_bit {
	
u16 feature;
	
u8 reg;
	
u8 bit;
	
u32 level;
	
u32 sub_leaf;
};

/* Please keep the leaf sorted by cpuid_bit.level for faster search. */

static const struct cpuid_bit cpuid_bits[] = {
	{ X86_FEATURE_APERFMPERF,       CPUID_ECX,  0, 0x00000006, 0 },
	{ X86_FEATURE_EPB,		CPUID_ECX,  3, 0x00000006, 0 },
	{ X86_FEATURE_INTEL_PT,		CPUID_EBX, 25, 0x00000007, 0 },
	{ X86_FEATURE_AVX512_4VNNIW,    CPUID_EDX,  2, 0x00000007, 0 },
	{ X86_FEATURE_AVX512_4FMAPS,    CPUID_EDX,  3, 0x00000007, 0 },
	{ X86_FEATURE_CAT_L3,		CPUID_EBX,  1, 0x00000010, 0 },
	{ X86_FEATURE_CAT_L2,		CPUID_EBX,  2, 0x00000010, 0 },
	{ X86_FEATURE_CDP_L3,		CPUID_ECX,  2, 0x00000010, 1 },
	{ X86_FEATURE_MBA,		CPUID_EBX,  3, 0x00000010, 0 },
	{ X86_FEATURE_HW_PSTATE,	CPUID_EDX,  7, 0x80000007, 0 },
	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },
	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
	{ X86_FEATURE_SME,		CPUID_EAX,  0, 0x8000001f, 0 },
	{ 0, 0, 0, 0, 0 }
};



void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
	u32 max_level;
	u32 regs[4];
	const struct cpuid_bit *cb;

	for (cb = cpuid_bits; cb->feature; cb++) {

		/* Verify that the level is valid */
		max_level = cpuid_eax(cb->level & 0xffff0000);
		if (max_level < cb->level ||
		    max_level > (cb->level | 0xffff))
			continue;

		cpuid_count(cb->level, cb->sub_leaf, &regs[CPUID_EAX],
			    &regs[CPUID_EBX], &regs[CPUID_ECX],
			    &regs[CPUID_EDX]);

		if (regs[cb->reg] & (1 << cb->bit))
			set_cpu_cap(c, cb->feature);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
H. Peter Anvin
104
78.79%
1
33.33%
He Chen
28
21.21%
2
66.67%
Total
132
100.00%
3
100.00%



u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf,
			     enum cpuid_regs_idx reg)
{
	const struct cpuid_bit *cb;
	u32 cpuid_val = 0;

	for (cb = cpuid_bits; cb->feature; cb++) {

		if (level > cb->level)
			continue;

		if (level < cb->level)
			break;

		if (reg == cb->reg && sub_leaf == cb->sub_leaf) {
			if (cpu_has(&boot_cpu_data, cb->feature))
				cpuid_val |= BIT(cb->bit);
		}
	}

	return cpuid_val;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
He Chen
101
100.00%
1
100.00%
Total
101
100.00%
1
100.00%


EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
H. Peter Anvin
185
41.20%
1
8.33%
He Chen
156
34.74%
2
16.67%
Fenghua Yu
33
7.35%
1
8.33%
Piotr Luc
17
3.79%
1
8.33%
Jacob Shin
13
2.90%
1
8.33%
Vikas Shivappa
12
2.67%
1
8.33%
Tom Lendacky
12
2.67%
1
8.33%
Thomas Renninger
9
2.00%
1
8.33%
Alexander Shishkin
8
1.78%
1
8.33%
Thomas Gleixner
3
0.67%
1
8.33%
Maxime Jayat
1
0.22%
1
8.33%
Total
449
100.00%
12
100.00%
Directory: arch/x86/kernel/cpu

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.